Rena XP2 Problems

Did you add any of the media from the Penguin to the XP or run them together for a few weeks?

If not you're going through another cycle. Check your water parameters and let us know what you're working with. A lower flow does help the water stay in the canister longer and might help but I think its something else.

Sounds like a bacterial bloom to me. Most likely your going thru a mini cycle of some sort. It will probably be a good idea to keep a close eye on your ammonia, nitrite, and nitrate levels just to make sure everything is going alright. I don't have a Rena filter myself, but I don't believe flow would be hindered too much by filter floss unless you really crammed it in there. The output of the spray nozzle should be a good indication of flow. My advice overall is to keep testing, wait it out, and keep up on regular water changes.

You'll just have to wait for the filter to cycle. That could take 1-2 months. I would of left the Penguin 150 alone, running it in addition to the xp2.

I use to have an xp3 and a marineland biowheel filter on my 33g tank.

I have an XP2 on my 55

How old is this tank and who lives in it?

Reason I ask is because if it's a really old tank and it's not densely populated, then changing filters shouldn't cause too much of a conundrum on your bacterial colonies.

Could it simply be that you kicked up a whole lotta debris from your substrate / surfaces when you added the new, faster flowing filter? That will take some time to clear. Give it a few days if that's the case.

Sometimes new filters (especially Renas due to the amount of sponge material) need to outgas a bit. (Lots of air bubbles will be forming and eventually escaping from the sponges in the canister.) The superfine bubbles may cause a temporary cloudiness.


I think you might want to up the flow rate to at least halfway. That is the place where I feel we get maximum filtration efficiency with these. I keep mine at max on my 55, but to clean cloudy water it's better to slow it down a bit.


If your biowheel has been consistently wet, I would suggest putting the Penguin back into action along with the Rena for at least a few days. This way you're not only adding significant extra filtration (which will hasten the demise of the cloudiness if it is debris) but you're also making sure you don't have any cycle problems.


So far I've been very satisfied with my XP2. (2 months) Good luck with yours.

Anglerman said:

Unfortunately I left my test kit at my brothers, so I will test the water tomorrow.
Chefkeith-What exactly are you saying?

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The new filter needs to cycle.

Anglerman said:

My tank is now back to square one, what about the gravel?

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Gravel doesn't help much, unless you had an Under Gravel Filter before.

Anglerman said:

So my tank is cloudy because of me changing the filter, so my fish are essentially at risk now?

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Yes the tank is cloudy because you changed the filter. Yes your fish are at risk. If you have some Prime you could add some to the water. Prime will detoxify Ammonia and Nitrites. Just be sure not to overfeed your fish for awhile.

Anglerman said:

I need to get this water tested asap, I will post after that. Thanks for answering guys.

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For my XP2's I use the foam sponges in the bottom basket and fill the top basket up with filter floss.
For your XP2, I'd keep the flow rate at it's maximum. Water flow helps cycling the filter. Point the spraybar back towards a corner if the flow is too great for your fish.